text: The price of West Texas crude sank to $37.65 (Â£24.99) a barrel, a drop of 5.8%, while Brent Crude fell 5.3% to $40.73 a barrel.
  The slumping price comes as OPEC - a group of the largest oil producing nations- refused to cut oil production.
  OPEC- whose production covers about 30% of the world's oil demand - met in Vienna last week to discuss production.
  The group has faced growing competition from new supplies, including in the US where techniques like fracking are used to tap previously hard-to-reach oil reserves.
  "The decision by OPEC members to keep oil production output at record high levels has seen oil prices plummet again," said Sanjiv Shah, chief investment officer of Sun Global Investments.
  The group had traditionally kept a tight rein on oil production to regulate price, but announced last Friday it will continue to pump out approximately 31.5 million barrels of oil a day, going past the group's former 30 million barrel target.
  In 2014 Saudi Arabia led OPEC in a decision to keep output high to defend its market share.
target: The price of oil fell to its lowest level since 2009 as global production continues to remain high.